Trying to make CSS div/layer invisible

I have a section of my page that I don't want to be visible or seen in any way (it needs to be there because it has some code that a dhtml feature I'm using depends on). I added the code in a div and added CSS to set the layer to visibility: hidden;

It works from the standpoint that nothing displays in the browser window, but it still creates white space and affects the layout of my page. What am I missing to make this truly invisible? The URL in question is http://www.campspofford.org/tour/index.php.